Gas-liquid mixed scrubbing type micro-bubble flotation device and method

Abstract

The invention relates to the technical field of oilfield water treatment, and discloses a gas-liquid mixed scrubbing type microbubble flotation device and method. The device comprises a main inlet pipe, a main inlet valve, a pressure boosting pump, a pump outlet pressure gauge, a pump outlet flow meter, a scrubbing type microbubble generator component, a dissolving microbubble releaser component, an inlet tangential inlet tank cyclone reduction pipe mouth, a cyclone gas flotation separation tank, and a monitoring and maintenance pipe mouth. When in use, an oil-gas-water mixed liquid is subjected to high-speed cutting by a pressure boosting pump impeller and atomization and mixing by scrubbing arc slot plates to form an emulsion. Through the dispersion release and centrifugal cyclone of the dissolving microbubble releaser component and the inlet tangential inlet tank cyclone reduction pipe mouth, sufficient number and density of normally distributed microbubbles with a particle size of 10-50 μm can be generated. Under the joint action of the cyclone centrifugal force and the microbubble flotation force in the separation tank, the water-in-oil emulsified mixture is effectively collided and crushed, and the physical demulsification and collision coalescence mechanical separation of fine oil droplets are realized. The separation efficiency is high and the adaptability to working conditions is strong.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield water treatment, and in particular to a gas-liquid mixed scrubbing type micro-bubble flotation device and method. Background Art

[0002] Bubble flotation devices are commonly used in oilfield water treatment equipment, such as the air flotation device disclosed in patent 201420341702.1 "A new type of compact air flotation separation device". The basic principle is to effectively use the effects of air flotation and cyclone to separate oil and water. The oily sewage enters the CFU (Compact Flotation Unit) container through two tangential inlets and generates cyclone. Under the action of centrifugal force, oil droplets and bubbles accumulate in the middle of the container and float up. Lighter bubbles and oil droplets quickly accumulate and coalesce in the middle of the CFU under the action of centrifugal force. At the same time, because the movement direction of oil droplets, bubbles and water is consistent and they all move upward, bubbles and oil droplets rise rapidly under the combined action of buoyancy and water drag, greatly shortening the rising time of bubbles and oil droplets, increasing the separation rate, and realizing efficient separation of oil and water. Bubbles adhere to suspended matter (oil droplets) and gradually form scum, which rises to the surface of sewage gas and liquid, bubbles break and precipitate, and pollutants gather and aggregate into agglomerates and are discharged through sewage discharge.

[0003] At present, the microbubble flotation devices used in the oilfield water treatment industry are mainly divided into the following categories based on the generation mechanism of flotation microbubbles: pressure dissolved gas (Dissolved Gas) precipitation of microbubbles, induced gas (Induced Gas) to create microbubbles, microporous media (Micro-porous Media) dispersed microbubbles, shear contact (Shear Contact) to divide microbubbles, chemical electrolysis (Electrolysis) precipitation of microbubbles, etc. For example, the way of producing microbubbles by induced gas jet, the high-speed water flow ejected by the ejector nozzle creates a negative pressure in the suction chamber, and sucks air from the suction pipe. After the water-gas mixture enters the throat section, it undergoes intense energy exchange, the air is crushed into tiny bubbles, and then goes straight into the diffusion section, the kinetic energy is converted into potential energy, further compressing the bubbles, increasing the solubility of air in water, and finally entering the flotation tank for gas-water separation.

[0004] However, the above-mentioned methods of generating flotation microbubbles have shown shortcomings in current industrial applications. The main characteristics are: limited efficiency in generating microbubbles, uneven normal distribution of microbubble size, the number and density of microbubbles in unit volume of liquid phase, low ratio of microbubble value in ideal state, and the number and quality of microbubbles as physical carriers for oil droplets to attach in the oil-gas-water separation zone are not good enough. Dead zones are also easily generated in the microbubble flotation separation zone, and the flotation effect of microbubbles is greatly affected by fluctuations in medium temperature and pressure. In particular, dissolved gas precipitation bubbles, shear contact foaming, etc. in oily wastewater treatment and other occasions often make shear emulsification more serious, which is not conducive to the subsequent separation process. Summary of the invention

[0005] In view of the problems and shortcomings of the prior art, the present invention discloses a gas-liquid mixed rubbing type microbubble flotation device, the technical problem to be solved is the above-mentioned defects shown by traditional gas flotation in current industrial applications, and can online adjust the microbubbles of the target diameter required for gas flotation in industrial applications, and the number density and normal distribution uniformity of the microbubbles in the liquid phase in an ideal state.

[0006] The technical solution of the present invention is as follows:

[0007] A gas-liquid mixing and scrubbing microbubble flotation device comprises an oil-gas-water three-phase mixing input section, an oil-gas-water three-phase empowering and pressurizing section, a dissolving microbubble section, a dissolving and releasing device microbubble generating section, a microbubble flotation three-phase separation section, and a diversion control and output section after the oil-gas-water three-phase separation, wherein the above sections are connected in sequence; the oil-gas-water three-phase mixing input section comprises a total inlet pipe, which is connected to a front-end production water pipeline and a flotation gas pipeline, and is used to receive the front-end production water and the flotation gas injected at the front end, and a total inlet valve is arranged behind the total inlet pipe; the oil-gas-water three-phase empowering and pressurizing section comprises a pressure boosting pump, the inlet of the pressure boosting pump is connected to the total inlet valve, and is provided with a pump outlet pressure gauge and a pump outlet flowmeter, which are used to create fluid pressure, flow, flow velocity, kinetic energy, and preliminarily mix the oil-gas-water three-phases; the dissolving microbubble section comprises a scrubbing microbubble generator assembly, which is connected to the outlet of the pressure boosting pump, and comprises a scrubbing sleeve, and a method for installing and connecting the front and rear scrubbing sleeves. Lan, and the upper and lower scrubbing arc slot plates installed inside the scrubbing sleeve, which are used to fully cut the coarse-grained microbubbles and dissolve them non-saturatedly under pressure; the dissolving releaser to generate microbubbles section includes a dissolving microbubble releaser component, an inlet tangential inlet tank swirl reduction pipe mouth, the front end of the dissolving microbubble releaser component is connected to the scrubbing microbubble generator component, and the rear end is connected to the inlet tangential inlet tank swirl reduction pipe mouth, which is used for the pressure drop at the releaser to trigger the dissolved gas to generate microbubbles; the microbubble The flotation three-phase separation section includes a cyclone gas flotation separation tank, which is connected to the inlet tangential inlet cyclone reducing pipe mouth, and is used to realize the three-phase separation of oil, gas and water in the tank; the post-separation of the oil, gas and water three-phase shunt control and output section includes a safety discharge pipe mouth, an oil discharge pipe mouth, a tank emptying pipe mouth, a pressure-stabilizing exhaust pipe mouth, a pressure-stabilizing air supply pipe mouth, a pressure safety relief pipe mouth, and a pressure relief shunt closed drain pipe, all of which are connected to the cyclone gas flotation separation tank, and are also provided with a separation tank body liquid level gauge and a tank body pressure gauge, which are used to monitor the three-phase shunt output.

[0008] Furthermore, the main inlet valve is connected to the pressure boosting pump via an eccentric reduction.

[0009] Furthermore, the cyclone gas flotation separation tank is provided with two symmetrical tangential inlet pipelines, each of which comprises a dissolved microbubble releaser assembly and an inlet tangential tank inlet cyclone reducing pipe opening.

[0010] Furthermore, a column is provided inside the cyclone gas flotation separation tank, and the cyclone separation area in the tank is a column-type unobstructed internal structure.

[0011] Furthermore, the two scrubbing arc trough plates are mirror-symmetrical in structure, and are arranged in parallel and opposite directions; the scrubbing arc trough plates are provided with multi-stage arc cone groove serrations. When the oil, gas, water and solid four-phase mixed fluid passes through the clear space between the two scrubbing arc trough plates, it is blocked and rebounded by the upper and lower arc serrations, forming an alternating tangency similar to a sine wave, so that the fluid can be fully oscillated and mixed, and solid accumulation and physical scaling are not easily formed in the arc groove of the serrations.

[0012] The process goal of setting up the scrubbing microbubble generator assembly is to produce saturated microbubbles with a particle size of 10 to 50 μm. The commonly used specifications of the scrubbing arc slot plate are 5-50 inches in length, the number of sawtooth levels is 15 to 75, and the recommended arc angle is 120 to 150°; (set according to the processing flow, microbubble number density and target particle size normal distribution)

[0013] Sawtooth Depth , sawtooth spacing , scrub the arc slot plate spacing ,

[0014] Where X and Y are the outer and inner diameters of the scrubbing sleeve, respectively (inches), γ is the surface tension, and r is the bubble radius. is the surface coverage, c is the surfactant concentration, and K is the adsorption equilibrium constant.

[0015] Based on the above-mentioned gas-liquid mixed rubbing and washing micro-bubble flotation device, the present invention provides a gas-liquid mixed rubbing and washing micro-bubble flotation method, comprising the following steps:

[0016] S1, oily wastewater and flotation gas injected from the front end form a three-phase mixed fluid and enter the main inlet pipe, and the fluid medium input is controlled by the main inlet valve;

[0017] S2, driven by the pressure booster pump, the three-phase mixed fluid obtains pressure increase, mixed fluid kinetic energy, flow stability, and full mixing of the oil, gas and water three-phase fluids;

[0018] S3, monitor the fluid pressure after the pump through the pump outlet pressure gauge, monitor the fluid flow after the pump through the pump outlet flow meter, and the three-phase fluid pre-cut and mixed by the pump rotating impeller enters the scrubbing micro-bubble generator assembly;

[0019] S4, the scrubbing type micro-bubble generator component mixes and disperses the coarse bubbles of different sizes and cuts them into dispersed fine bubbles, and the micro-bubbles are quickly dissolved in the non-saturated dissolved liquid phase under the action of pressure energy and impact kinetic energy;

[0020] S5, the fluid is evenly divided into two symmetrical tangential inlet pipelines through a three-way connection, and the dissolved gas in the liquid phase is released and expanded to form dispersed microbubbles through the dissolved microbubble releaser assembly on each tangential inlet pipeline and the inlet tangential tank swirl reduction pipe opening by using the pressure drop principle;

[0021] S6, the inlet tangential inlet cyclone reducing pipe makes the three-phase fluid enter the cyclone gas flotation separation tank tangentially along the tank wall at a high flow rate, forming a columnar cyclone in the tank. Under the action of the cyclone centrifugal force, the oil droplets and bubbles in the tank accumulate in the middle of the container and float up to achieve oil-water separation.

[0022] Furthermore, in step S3, the fluid pressure is adjusted by the frequency conversion and pressure control valve of the pressure boosting pump. The above operation is matched with the sawtooth depth, sawtooth spacing, and scrubbing arc slot plate spacing parameters of the scrubbing type microbubble generator assembly, so that the generated microbubble particle size distribution range is 10 to 50 μm.

[0023] Compared with the prior art, the beneficial technical effects achieved by the present invention include:

[0024] 1. Two parallel reverse staggered sawtooth rubbing arc trough plates can obtain bubbles with ideal diameter by setting the plate spacing, sawtooth shape size and number of stages, thus solving the problem of microbubble particle size of microbubble flotation device;

[0025] 2. The valve at the fluid inlet controls the gas-liquid two-phase flow ratio. The pressure booster pump provides pressure energy. The high-speed pump impeller disperses the gas-liquid mixed fluid evenly. The pressure energy is converted into velocity energy on the arc groove plate surface in the narrow channel. The velocity energy efficiently dissolves the flotation gas in the liquid phase under the impact of the cross flow, solving the gas-liquid mixed dissolution ratio problem of the micro-bubble flotation device.

[0026] 3. After the gas and liquid are dissolved in the scrubbing micro-bubble generator assembly, a release device is provided at the double tangential entrance of the mixed fluid entering the separation tank, and the mixed fluid diffuses 360 degrees in the annular space of the cyclone zone, solving the problem of gas-liquid dispersion uniformity of the micro-bubble flotation device;

[0027] 4. After the oil-gas-water mixture undergoes physical high-speed cutting by the impeller of the high-speed pressure boost pump and impact atomization and mixing by the arc trough plate, a certain degree of emulsion will be formed. Then, under the action of the tangential inlet releaser and centrifugal cyclone when entering the separation tank, a large number of normally distributed microbubbles with a particle size of 10-50μm are generated. Under the combined action of the cyclone centrifugal force and the microbubble flotation force in the separation tank, the water-in-oil emulsified mixture is effectively collided and crushed, realizing the physical demulsification and collision coalescence mechanical separation of fine oil droplets, solving the emulsification problem of the gas-liquid mixing process of the microbubble flotation device, with high separation efficiency and strong adaptability to working conditions;

[0028] 5. The device can create sufficiently high pressure energy and fluid kinetic energy by designing and selecting a high-lift pressure boosting pump, achieving a higher effective gas-liquid dissolution ratio, sufficient number and density of microbubbles, and vertical surrounding full coverage under the action of the cyclonic centrifugal force of the phase density difference in the separation tank, solving the problem of collision and combination efficiency of microbubbles and oil droplets in the microbubble flotation device;

[0029] 6. The cyclone separation area in the CFU tank adopts a column-type unobstructed internal structure, and the fluid moves in a three-dimensional manner, which solves the problem of dead corners in the static area of ​​the bubbles in the liquid phase distribution of the micro-bubble flotation device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the structure of the gas-liquid mixed scrubbing micro-bubble flotation device of the present invention;

[0031] Figure 2 It is a structural schematic diagram of another angle of the present invention;

[0032] Figure 3 It is a side perspective view of the present invention;

[0033] Figure 4 It is a schematic diagram of the overall and separate structures of the scrubbing type micro-bubble generator assembly;

[0034] Figure 5 for Figure 4 Middle A is a partial enlarged schematic diagram;

[0035] Figure 6 This is a schematic diagram of the structure of the arc trough plate;

[0036] Figure 7 It is a schematic diagram of the internal structure of the cyclone gas flotation separation tank;

[0037] Notes in the figure: 1. Main inlet pipe; 2. Main inlet valve; 3. Pressure booster pump; 4. Pump outlet pressure gauge; 5. Pump outlet flow meter; 6. Scrubbing type micro-bubble generator assembly; 61. Scrubbing sleeve; 62. Scrubbing sleeve installation connection flange; 63. Scrubbing arc slot plate; 7. Safety discharge pipe outlet; 8. Oil discharge pipe outlet; 9. Tank body emptying pipe outlet; 10. Dissolved micro-bubble releaser assembly; 11. Inlet tangential inlet tank cyclone reduction pipe outlet; 12. Cyclone gas flotation separation tank; 13. Separation tank body liquid level gauge; 14. Pressure stabilizing exhaust pipe outlet; 15. Pressure stabilizing air supply pipe outlet; 16. Pressure safety relief pipe outlet; 17. Pressure relief diversion closed drain pipe; 18. Tank body pressure gauge. DETAILED DESCRIPTION

[0038] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0039] like Figure 1-3 As shown, the gas-liquid mixing and scrubbing microbubble flotation device of the present invention includes an oil-gas-water three-phase mixing input section, an oil-gas-water three-phase empowering and pressurizing section, a dissolving microbubble section, a dissolving and releasing device to generate microbubbles, a microbubble flotation three-phase separation section, and a diversion control and output section after the oil-gas-water three-phase separation; the oil-gas-water three-phase mixing input section includes a total inlet pipe 1 and a total inlet valve 2, which are used to receive the flotation gas injected from the front end and the front end; the oil-gas-water three-phase empowering and pressurizing section includes a pressure boosting pump 3, a pump outlet pressure gauge 4, and a pump outlet flow meter 5, which are used to create fluid pressure and flow, and preliminarily mix the oil-gas-water three phases; the dissolving microbubble section includes a scrubbing microbubble generator assembly 6, which is used to mix the coarse-particle microgas The bubbles are fully cut and dissolved non-saturatedly under pressure; the dissolving releaser generates microbubbles, including a dissolving microbubble releaser assembly 10 and an inlet tangential cyclone reduction pipe port 11, which is used for the pressure drop at the releaser to induce the dissolved gas to generate microbubbles; the microbubble flotation three-phase separation section includes a CFU cyclone gas flotation separation tank 12, which is used to achieve the three-phase separation of oil, gas and water in the tank; the post-separation shunt control and output section of the oil, gas and water three-phase separation includes a safety discharge pipe port 7, an oil discharge pipe port 8, a tank emptying pipe port 9, a separation tank body liquid level gauge 13, a pressure-stabilizing exhaust pipe port 14, a pressure-stabilizing air supply pipe port 15, a pressure safety discharge pipe port 16, a pressure relief shunt closed drain pipe 17, and a tank body pressure gauge 18, which are used to monitor the three-phase shunt output.

[0040] Among them, the main inlet valve 2 is connected to the pressure boosting pump 3 through an eccentric reduction;

[0041] The cyclone gas flotation separation tank 12 is provided with two symmetrical tangential inlet pipelines, each of which includes a dissolved microbubble releaser assembly 10 and an inlet tangential tank inlet cyclone reducing pipe opening 11 .

[0042] like Figure 4 As shown, the scrubbing type micro bubble generator assembly 6 includes a scrubbing sleeve 61, two front and rear scrubbing sleeve mounting connection flanges 62, and two upper and lower scrubbing arc slot plates 63 installed inside the scrubbing sleeve. Figure 4-6 As shown, the upper and lower washing arc groove plates 63 are mirror-symmetrical in structure and are arranged in parallel and face-to-face inversely; the washing arc groove plates are provided with multi-stage arc-shaped conical groove serrations. Figure 5 (a) is a three-dimensional structural diagram of the relative installation positions of two arc-cleaning slot plates. Figure 5(b) is a front view of the relative installation positions of the two arc-washing slot plates; Figure 5 (c) is a top view of the relative positions of the two arc trough plates. Figure 5 As shown in (c), the arc cone groove serrations of the two scrubbing arc trough plates form an alternating arc cone groove serration structure due to the reverse arrangement of the upper and lower scrubbing arc trough plates. This structure allows the oil, gas, water and solid four-phase mixed fluid to pass through the net space between the two scrubbing arc trough plates. After being blocked and rebounded by the upper and lower arc cone groove serrations, it forms an alternating tangency similar to a sine wave, so that the fluid can be fully oscillated and mixed, and solid accumulation and physical scaling are not easily formed in the arc groove of the serrations.

[0043] The process goal of setting up the scrubbing type microbubble generator assembly is to produce saturated distributed microbubbles with a particle size of 10 to 50 μm. To achieve this goal, the model, specification, and size of the scrubbing arc trough plate as well as the number of parallel and serial connections need to be configured according to the processing capacity of the air flotation equipment. The number of parallel and serial connections is determined based on the design conditions and process requirements, and is verified through on-site test results.

[0044] The common specifications of the arc trough plate are 5-50 inches in length, 15-75 sawtooth levels, and the recommended arc angle is 120-150°; (set according to the processing flow, microbubble number density and target particle size normal distribution)

[0045] Sawtooth Depth , sawtooth spacing , scrub the arc slot plate spacing ,

[0046] Where X and Y are the outer and inner diameters of the scrubbing sleeve, respectively (inches), γ is the surface tension, and r is the bubble radius. is the surface coverage, c is the surfactant concentration, and K is the adsorption equilibrium constant.

[0047] The design parameters of the sawtooth scrubbing arc slot plate, such as the tooth peak height difference gap ratio, tooth pitch width ratio, tooth arc offset ratio, etc., all affect the micro bubble particle size and its normal distribution. The above parameters provided by the present invention can achieve the most concentrated bubble particle size distribution range of 10-50 μm.

[0048] Based on the above-mentioned gas-liquid mixed rubbing and washing micro-bubble flotation device, the present invention provides a gas-liquid mixed rubbing and washing micro-bubble flotation method, comprising the following steps:

[0049] S1, oily wastewater and flotation gas injected from the front end form a three-phase mixed fluid and enter the main inlet pipe 1, and the fluid medium input is controlled by the main inlet valve 2;

[0050] S2, driven by the pressure boosting pump 3, the three-phase mixed fluid obtains pressure increase, mixed fluid kinetic energy, flow stability, and full mixing of the oil, gas and water three-phase fluids;

[0051] S3, monitor the fluid pressure after the pump through the pump outlet pressure gauge 4, monitor the fluid flow after the pump through the pump outlet flow meter 5, and the three-phase fluid pre-cut and mixed by the pump rotating impeller enters the scrubbing micro-bubble generator assembly 6;

[0052] S4, the scrubbing type micro-bubble generator assembly 6 mixes and disperses the coarse bubbles of different sizes and cuts them into dispersed fine bubbles, and the micro-bubbles are quickly dissolved in the non-saturated dissolved liquid phase under the action of pressure energy and impact kinetic energy;

[0053] S5, the fluid is evenly divided into two symmetrical tangential inlet pipelines through a three-way connection, and the dissolved gas dissolved in the liquid phase is released and expanded to form dispersed microbubbles through the dissolved microbubble releaser assembly 10 and the inlet tangential tank swirl reduction pipe port 11 on each tangential inlet pipeline using the pressure drop principle;

[0054] S6, the inlet tangential inlet cyclone reducing pipe 11 allows the three-phase fluid to be injected into the cyclone gas flotation separation tank 12 along the tank wall tangentially at a high flow rate, forming a columnar cyclone in the tank. Under the action of the cyclone centrifugal force, the oil droplets and bubbles in the tank accumulate in the middle of the container and float up to achieve oil-water separation.

[0055] The separation tank is also provided with a safety discharge pipe 7 of the flotation device, which can discharge the fluid released by the safety valve and other emptied fluids; an oil discharge pipe 8 of the flotation device, which discharges the oil after three-phase separation; a tank body emptying pipe 9 of the flotation device, which can timely empty the fluid in the tank when the device is shut down for inspection or maintenance, and can be used as a purge port to purge the inside of the device; a separation tank body liquid level gauge 13, which is used to monitor the liquid level in the separation tank to ensure the diversion ratio of the oil-water two-phase overflow; a pressure-stabilizing exhaust pipe 14, which discharges the flotation gas and The gas is discharged when needed, or returned to the main inlet end to be recycled as flotation gas; the pressure-stabilizing air supply pipe port 15 is used to supplement the insufficient pressure in the tank. During the pressurizing stage at startup, or when the flotation gas at the front end is insufficient, the pressure in the tank may continue to drop. At this time, it is necessary to supply air for pressure stabilization; the pressure safety relief pipe port 16 is used to timely release the pressure when the equipment is over-pressured or in a fire or explosion condition, so as to ensure the safety of the pressure device; the pressure relief diversion closed discharge pipe 17 can divert the fluid discharged by the safety valve into a safe closed discharge system; the tank pressure gauge 18 is used to monitor the working pressure of the flotation separation tank.

[0056] See also Figure 7The cyclone separation area in the CFU tank adopts a column-type unobstructed internal structure. The fluid moves in a three-dimensional circle in the tank, and there is no dead static area in the distribution of bubbles in the liquid phase. The entire gas-liquid mixing and washing micro-bubble flotation process is further described as follows:

[0057] The oily wastewater from the front end (usually produced water from the oilfield exploitation process) and the flotation gas injected at the front end (usually nitrogen or petroleum associated gas) form a three-phase mixed fluid and enter the main inlet pipe 1. Immediately thereafter, the main inlet valve 2 controls the switch of the fluid medium input of the entire gas flotation device. Then, it is connected to the pressure boosting pump 3 through an eccentric reduction. Driven by the pressure boosting pump 3, the three-phase mixed fluid obtains pressure increase, flow stability, and full mixing of the oil, gas and water three-phase fluids. The fluid pressure after the pump is monitored by the pump outlet pressure gauge 4, and the fluid flow after the pump is monitored by the pump outlet flowmeter 5. The three-phase fluid pre-cut and mixed by the rotating impeller of the pump enters the core part of the device, the scrubbing micro-bubble generator component 6, which further fully mixes and disperses the coarse bubbles of different sizes and The microbubbles are cut into dispersed microbubbles, and the microbubbles are quickly dissolved in the unsaturated dissolved liquid phase under the action of pressure energy. The three-way connection behind the scrubbing microbubble generator assembly 6 will divide the fluid into two symmetrical tangential inlet pipelines, each of which includes a dissolved microbubble releaser assembly 10 and an inlet tangential inlet tank swirl reduction pipe 11. The dissolved microbubble releaser assembly 10 adopts the pressure drop principle or releases and expands the dissolved gas dissolved in the liquid phase to form dispersed microbubbles. Then, the inlet tangential inlet tank swirl reduction pipe 11 will make the three-phase fluid tangentially injected into the flotation separation tank along the tank wall at a higher flow rate, forming a columnar swirl in the tank. In this process, due to the support of the pump booster, a 3.0-6.0g (higher than the conventional strong flotation swirl CFU) will be generated. 1.0-2.0g) cyclonic centrifugal force, in the CFU cyclonic air flotation separation tank 12, oil droplets and bubbles are accumulated in the middle of the container and float under the action of centrifugal force. Lighter bubbles and oil droplets are rapidly accumulated and coalesced in the middle of the CFU under the action of centrifugal force. At the same time, since the movement direction of oil droplets, bubbles and water is consistent and they all move upward, bubbles and oil droplets rise rapidly under the combined action of buoyancy and water drag, which greatly shortens the rising time of bubbles and oil droplets, improves the separation rate, and realizes efficient separation of oil and water.

[0058] The cleverness of the characteristic function realization and problem solving of the device of the present invention lies in: the gas-liquid mixing ratio can be freely adjusted, the pump not only provides the pressure energy required for dissolving microbubbles, but also can crush and mix the three-phase fluid, and then the zigzag rubbing arc groove plates arranged in a reverse array are used to achieve sufficient dilution and saturated dissolution of the microbubbles, and finally dispersed microbubbles with ideal diameter and saturated density are generated through the releaser.

[0059] In practical applications, the standard product is 100 m3 Taking the CFU with a processing capacity of / h as an example, in actual industrial application, its actual processing capacity is 0~100 m 3 / h, and the processing capacity of different working conditions is also changing with the year, which requires the pressure booster pump and scrubbing micro-bubble generator components to adapt to the immediate working conditions. When the actual working condition processing capacity is less than 100m 3 / h, the difference needs to be automatically adjusted through the CFU tank output water return branch pipe + flow meter + control valve combination device. While maintaining the pressure booster pump and scrubbing micro bubble generator components stable for 100 m 3 / h of liquid flow, while the part of the water returned from the CFU tank can be treated twice, further improving the treatment process indicators of oil-water separation.

[0060] Compared with other gas flotation microbubble filling devices: For example, Chinese patent CN201610807466 "A gas flotation microbubble filling device for petroleum water treatment and its use method" discloses a gas flotation microbubble filling device, the mechanism of microbubble generation is liquid phase cyclone flushing microporous surface airflow cutting type, which is a guide vane plus cylindrical surface microporous tube structure; while the oil, gas and water three-phase empowering boosting section of the present invention, the physical mechanism and structural form of microbubble generation are completely different. The mechanism of microbubble generation of the present invention is three-phase mixed flow horizontal wave oscillation scrubbing type, which is a parallel reverse staggered zigzag scrubbing arc trough plate structure. Such a structure can achieve sufficient dilution and saturated dissolution of microbubbles, and finally generate dispersed microbubbles with ideal diameter and saturated density through the releaser, which is difficult to achieve with other gas flotation microbubble filling devices.

[0061] Compared with the device without the added arc trough plate structure, such as the gas-liquid mixed microbubble generator composed of an ejector (Venturi tube) + a circulating pump, its obvious feature is that no matter how the gas-liquid ratio is adjusted, the gas-liquid ratio that effectively dissolves and releases microbubbles is difficult to exceed 10% (volume ratio), and the excess gas phase cannot form effective flotation microbubbles (effective particle size 10-50μm, the optimal microbubble particle size is 15-30μm) but exists in the form of airflow, which not only cannot produce flotation, but also disturbs the centrifugal cyclone separation flow field in the CFU tank, resulting in a decrease in the overall separation performance. The device of the present invention adds a scrubbing arc slot plate structure, which can fully oscillate, crush and mix the airflow and liquid to form microbubbles that can collide and combine with the oil droplets in the liquid phase. Without causing disturbances in the centrifugal cyclone separation flow field in the CFU tank, the gas-liquid mixing ratio can reach more than 2 / 3 (volume ratio), ensuring that there are a sufficient number of microbubbles to form a sufficiently high microbubble distribution density, thereby ensuring an absolutely high probability of microbubbles colliding and coalescing with the oil droplets in the liquid phase, thereby achieving efficient oil-water separation.

[0062] In summary, the beneficial effects obtained by the present invention include:

[0063] 1. Compared with the traditional jet-type microbubble components, the scrubbing type microbubble generator assembly can withstand greater fluid impact strength, and has better anti-scaling and anti-clogging properties. The scrubbing type is that all the three phases of oil, gas and water must pass through the scrubbing arc trough plate surface (100% of the liquid participates in the dissolution of microbubbles), and its pressure booster pump directly pressurizes the input fluid, while the jet type in industrial applications is only a bypass circulation type (20% of the treated output water participates in the dissolution of microbubbles), and its circulation pump only pressurizes 20% of the external circulating dissolved gas water, and does not generate front-end pressurization of the input device fluid, so the scrubbing type can also achieve saturated dissolved gas volume in the liquid phase at a higher pressure.

[0064] 2. The flotation separation zone in the gas-liquid mixed scrubbing microbubble device can produce a certain proportion of microbubbles with a particle size of 5-15μm, while the particle size of microbubbles produced in the flotation separation zone in the jet microbubble device is usually 30-150μm. Only when the particle size of the microbubbles is less than 15μm, can the microbubbles pass through the oil-water interface membrane and play a more efficient physical demulsification effect on the oil droplets in the emulsified state (oil in water). Otherwise, the chemical demulsification assistance of the agent is required for the oil-water emulsion. Therefore, in comparison, the gas-liquid mixed scrubbing microbubble device does not need to set up a chemical agent auxiliary device.

[0065] 3. Compared with the jet type microbubble device, the gas-liquid mixed scrubbing type microbubble device has a simpler supporting pipeline process and automated instrument control valve, and the control and operation will be simpler, more reliable and stable.

[0066] 4. The most critical functional element of the device - the zigzag arc-washing slot plate arranged in a reverse array, is installed in a flange-connected pipe. It has a compact structure, small space, light weight, and is easy to install and disassemble. During industrial application, it can be adjusted or replaced with a more suitable structural type (structural form and size optimized by CFD fluid simulation) according to the required particle size and density of microbubbles.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention, such as the design monomer structure form of the scrubbing type microbubble generating device, the shape and configuration level of the scrubbing arc groove plate are different based on the present technical scheme, the principle method of manufacturing vortex and the centrifugal separation form are different, each specific functional section or key functional element in the device has different naming or selection, the proprietary design form of the core functional element is different, the combination configuration process method is different, etc., should all be included in the protection scope of the present invention.

Claims

1. Gas-liquid mixed scrubbing type micro-bubble flotation device, characterized by: It includes an oil-gas-water three-phase mixed input section, an oil-gas-water three-phase empowerment and pressurization section, a dissolving microbubble section, a dissolving releaser microbubble generation section, a microbubble flotation three-phase separation section, and a diversion control and output section after the oil-gas-water three-phase separation, and the above sections are connected in sequence; the oil-gas-water three-phase mixed input section includes a total inlet pipe, which is connected to the front-end production water pipeline and the flotation gas pipeline, and a total inlet valve is provided behind the total inlet pipe; the oil-gas-water three-phase empowerment and pressurization section includes a pressure boosting pump, the inlet of the pressure boosting pump is connected to the total inlet valve, and a pump outlet pressure gauge and a pump outlet flowmeter are provided; the dissolving microbubble section includes a scrubbing type microbubble generator assembly, and the scrubbing type microbubble generator assembly is connected to the pressure boosting pump outlet, including a scrubbing sleeve, and two front and rear scrubbing sleeve installation connections. The connecting flange and the upper and lower scrubbing arc slot plates installed inside the scrubbing sleeve; the dissolving releaser generating microbubble section includes a dissolving microbubble releaser assembly and an inlet tangential inlet tank cyclone reduction pipe mouth, the front end of the dissolving microbubble releaser assembly is connected to the scrubbing microbubble generator assembly, and the rear end is connected to the inlet tangential inlet tank cyclone reduction pipe mouth; the microbubble flotation three-phase separation section includes a cyclone gas flotation separation tank, which is connected to the inlet tangential inlet tank cyclone reduction pipe mouth; the oil, gas and water three-phase separation post-diversion control and output section includes a safety discharge pipe mouth, an oil discharge pipe mouth, a tank body emptying pipe mouth, a pressure-stabilizing exhaust pipe mouth, a pressure-stabilizing air supply pipe mouth, a pressure safety discharge pipe mouth, and a pressure relief diversion closed discharge pipe, all of which are connected to the cyclone gas flotation separation tank, and are also provided with a separation tank body level gauge and a tank body pressure gauge; The cyclone gas flotation separation tank is provided with columns inside, and the cyclone separation area in the tank is a column-type unobstructed internal structure; The two rubbing arc groove plates are mirror-symmetrical in structure and are arranged in parallel and opposite directions up and down; the rubbing arc groove plates are provided with multi-stage arc cone groove serrations.

2. The gas-liquid mixed scrubbing type micro-bubble flotation device according to claim 1, characterized in that: The main inlet valve is connected to the pressure boosting pump via an eccentric reduction.

3. The gas-liquid mixed scrubbing type micro-bubble flotation device according to claim 1, characterized in that: The cyclone gas flotation separation tank is provided with two symmetrical tangential inlet pipelines, each of which comprises a dissolved microbubble releaser assembly and an inlet tangential tank inlet cyclone reducing pipe opening.

4. The gas-liquid mixed scrubbing type micro-bubble flotation device according to claim 1 is characterized in that: The length of the scrubbing arc slot plate is 5-50 inches, the number of sawtooth levels is 15-75, and the arc angle is 120-150°, which is set according to the processing flow rate, microbubble number density and target particle size normal distribution; Sawtooth Depth , sawtooth spacing , scrub the arc slot plate spacing , Where X and Y are the outer and inner diameters of the scrubbing sleeve, respectively (inches), γ is the surface tension, and r is the bubble radius. is the surface coverage, c is the surfactant concentration, and K is the adsorption equilibrium constant.

5. A gas-liquid mixing and rubbing microbubble flotation method based on the gas-liquid mixing and rubbing microbubble flotation device according to claim 1, characterized in that: The steps include: S1, oily wastewater and flotation gas injected from the front end form a three-phase mixed fluid and enter the main inlet pipe, and the fluid medium input is controlled by the main inlet valve; S2, driven by the pressure booster pump, the three-phase mixed fluid obtains pressure increase, mixed fluid kinetic energy, flow stability, and full mixing of the oil, gas and water three-phase fluids; S3, monitor the fluid pressure after the pump through the pump outlet pressure gauge, monitor the fluid flow after the pump through the pump outlet flow meter, and the three-phase fluid pre-cut and mixed by the pump rotating impeller enters the scrubbing micro-bubble generator assembly; S4, the scrubbing type micro-bubble generator component mixes and disperses the coarse bubbles of different sizes and cuts them into dispersed fine bubbles, and the micro-bubbles are quickly dissolved in the non-saturated dissolved liquid phase under the action of pressure energy and impact kinetic energy; S5, the fluid is evenly divided into two symmetrical tangential inlet pipelines through a three-way connection, and the dissolved gas in the liquid phase is released and expanded to form dispersed microbubbles through the dissolved microbubble releaser assembly on each tangential inlet pipeline and the inlet tangential tank swirl reduction pipe opening by using the pressure drop principle; S6, the inlet tangential inlet cyclone reducing pipe makes the three-phase fluid enter the cyclone gas flotation separation tank tangentially along the tank wall at a high flow rate, forming a columnar cyclone in the tank. Under the action of the cyclone centrifugal force, the oil droplets and bubbles in the tank accumulate in the middle of the container and float up to achieve oil-water separation.

6. The gas-liquid mixed scrubbing microbubble flotation method according to claim 5, characterized in that: It also includes the following steps: in step S3, the fluid pressure is adjusted by the frequency conversion and pressure control valve of the pressure boosting pump, and the above operation is matched with the sawtooth depth, sawtooth spacing, and scrubbing arc groove plate spacing parameters of the scrubbing type microbubble generator assembly, so that the generated microbubble particle size distribution range is 10 to 50 μm.

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